Presently a large variety of keys and mechanical type locking cylinders, wherein the key has on its surfaces and/or edges, the recesses or embossments that allow rotating movement of the rotor of the cylinder, upon none of the pistons preventing it as all of them are flush with the rotation surface, are known. This enables the lock to be operated.
Electronic devices that allow the lock to be opened by means of magnetic keys and remote control are also known.
In these systems alluded to if one loses a key, or else the remote control and its type and combination, respectively, are not known, normal opening of the lock becomes impossible and it will only be opened if the same is partially or totally destroyed.
In order to prevent a lost key from operating the cylinder, the same must be changed.
In the case of combined action locks, the transmission of the code or communication between the key and the lock, is done by means of an energy receiving coil, in other words, by means of electromagnetic induction. For this purpose the key includes in its electronic code circuit a ROM memory and a coil to capture the energy coming from the communication coil of the locking cylinder and to send the code to the control circuit, also done by magnetic induction.